1. Field of the Invention
This invention relates to menstrual cycle indicators which provides a visual display of the number of days since the start of a woman's menstrual cycle, and particularly an indicator which uses a digital watch module as the combined day indicator and clock source.
2. Description of the Prior Art
A woman's menstrual cycle is approximately one month long and during a portion that lasts approximately ten days, she is fertile. If the woman wishes to practice the rhythm method of birth control or if she wishes to know on which days she is fertile, she needs some type of method or device to indicate the number of days that have passed since she menstruated.
To date, several methods and devices have been used for determining the number of days that have passed since the start of a menstrual cycle. These methods, however, have a number of drawbacks.
The simplest method is to mark off the number of days on a calendar from the start of the woman's menstrual cycle. This method has two drawbacks. First, the woman must remember to mark off each day as it passes, otherwise she may believe that fewer days have passed from the start of her menstrual cycle. Second, if she incorrectly counts the number of days from the start of her menstrual cycle, she will also make a mistake about the number of days that have passed since the start of her menstrual cycle. A foolproof method is needed so a woman cannot lose track of the number of days since the start of her menstrual cycle. Furthermore, the device should be portable so a woman can take her device with her while traveling and it should also be simple and inexpensive.
Various attempts to achieve these objectives are menstrual cycle indicating devices disclosed in U.S. Pat. Nos. 2,979,884 issued to Gordon, 3,011,303 issued to Dickinson, 3,031,654 issued to Galen, 3,152,437 issued to Vasselli, and 3,472,018 issued to Papworth. These inventions use electromechanical clocks and have a number of drawbacks intrinsic to their designs. A primary drawback is the devices are not portable.
The device disclosed in U.S. Pat. No. 3,031,654 issued to Galen, does contemplate the use of a battery to provide power for an alternative design, but the relatively large amount of power required to drive the motor would dictate the use of a relatively powerful and therefore relatively expensive and bulky battery.
The displays of all of the electromechanical clock menstrual cycle indicators use a combination of hands or dials to display information; in the event of a power failure or some other event that would cause the clock mechanism to malfunction, the unit would still display this information. Therefore, the user could read the displayed information and not realize that the unit has been turned off due to a power failure or some other event. Some devices, U.S. Pat. No. 3,031,654 issued to Galen being typical, do have a light to indicate a power failure. However, if power is turned off and is later applied to the unit, the light, which indicates power is on, would light again so the user would not know that the invention had been turned off for a period of time. Thus, it would still display erroneous data without indicating this to the user.
All the inventions described above include knobs that project out either the front or the rear of the unit for setting or resetting the unit. The drawback of these knobs is that someone could inadvertently reset the unit. This is particularly likely if the clock is accessible to a child.
The device disclosed in U.S. Pat. No. 4,151,831 issued to Lester, uses recorded variations of a woman's temperature during her menstrual cycle to predict when she will ovulate, which is the start of the fertile portion of her menstrual cycle. The drawback of this menstrual cycle indicator is that it is quite complex in that it requires several different pieces of equipment to record the data and perform the necessary calculations to determine the start of the woman's cycle and provide back up storage of the information. This greatly increases the cost of the equipment.
It is therefore an object of the present invention to provide a menstrual cycle indicator that will indicate the number of days that have passed since the start of a woman's cycle and indicate during what portion of the menstrual cycle she is fertile.
It is another object of the present invention to provide a menstrual cycle indicator that is simple to operate, inexpensive and portable.
It is an additional object of the invention to provide a mechanism to prevent the display of erroneous information in case of a failure of the power source of the unit.
It is a further object of this invention to protect the resetting mechanism from inadvertent actuation.